1. Field of the Invention
This invention relates to blends of cotton and polyester copolymer binder fibers and to batts made from such blends. The batts are made by means of a thermal bonding process; and they are durable enough to withstand the stresses of repeated washings. The blends are of a high bulk and a low density.
2. Description of the Prior Art
U.S. Pat. No. 4,685,914, issued Aug. 11, 1987 (Personal Products) teaches the manufacture of an absorbent pad by heat fusing a combination of absorbent fibers and binder fibers. Absorbent fibers can be wood pulp, rayon, cellulose acetate, flax, hemp, jute, ramie, cotton, and the like. Binder fibers are polyester. One pad, using a blend of polyester staple and polyester binder fibers and a blend of acrylic fibers and polyester binder fibers, is about 20-25% binder fibers and is bonded at about 315.degree. F.
European Patent publication 227,914 seems to teach consolidation of cotton swabbing by superficially fusing thermoplastic fibers uniformly distributed throughout the cotton. The temperature for the fusing appears to be about 250.degree. F.
Japanese Publications, J60029182A (Toray) and J60040239A (Kanegafuchi), available in abstract form, teach manufacturing a blend of fibers; and fusing the blend by thermal means. The fibers can be selected from a list of relatively high melting materials including polyester, polypropylene, polyacrylic, cotton, wool, hemp, rayon, and the like; and a list of binder fibers including copolyester, polyolefin, and the like.
U.S. Pat. No. 4,769,022, issued Sept. 6, 1988 (3M) teaches the preparation of a pad made by heating a blend of 50/50, wt. cotton and polyester for 20 seconds at 285.degree. F.
Polyester Staple for Thermally Bonded Nonwovens, by W. K. Kwok, et al., Nonwovens Industry, June, 1988, teaches that particular polyester binder fiber products can be used to make thermally bondable blends of fibers. Cotton is not mentioned as a candidate fiber for the blends.